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Double Slit

  1. Apr 21, 2008 #1
    hey everybody, I am doing a physics project on the double slit experiment. (I know all the physics and math behind it so don't get into that stuff :P) I was just wondering if people had any suggestions on how to conduct the experiment, I was thinking of cutting two extremely small (knife blade) slits into a tinfoil (or something else of similar make up) plate (about 1mm apart) and shining a light directly at the plate, thus creating the famous interference pattern. I am also wondering if I need coherent light or not?

    So, suggestions on how to conduct, and the light question.
  2. jcsd
  3. Apr 21, 2008 #2
    I am pretty sure that is has to be coherent for best resuts, more like a laser-ish thing/light cannon.

    Here is how it should look like in theory:

    http://www.colorado.edu/physics/2000/schroedinger/two-slit2.html [Broken]

    Post some pictures of it when you do it! ;)
    Last edited by a moderator: May 3, 2017
  4. Apr 21, 2008 #3
    What kind of a laser would I need for this to fully work? Like, a $5 laser from a dollar store or something that is quite large? I'm assuming that I need to engulf the two slits entirely.
  5. Apr 21, 2008 #4

    This one is rather complicated, but it mentions a diode laser
    Which is also know as semi-conductor laser.

    Which, I think, is a 99cents laser

    So you shouldn't have any problem with that
  6. Apr 21, 2008 #5
    Ok, thanks for your replies. I'm gonna have to do some experimenting with the lasers and stuff but it should work out ok. I will post some pictures if everything goes ok.
  7. Apr 22, 2008 #6

    Andy Resnick

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    The coherence area of the beam needs to be larger than the illuminated area- a raw diode laser beam will not work.

    Focusing the laser (or any light source, really) onto a pinhole,collecting the transmitted light and illuminating your slits, OTOH, will work nicely.
  8. Apr 22, 2008 #7
    Ahhhh, ok. That would work a bit better than trying to fashion something out of of a bunch of laser diodes.
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